Charger for explosives



1946- E. K. LEFlEN 2,405,507

CHARGER FOR EXPLOSIVES Filed Nov. 21, 1942 INVENTOR.

BY EDWARD K. LEFRE/V W Q\Ma.-

Patented Aug. 6, 1946 CHARGER FOR EXPLOSIVES Edward K. Lefren, PortEwen, N. Y., assignor to Hercules Powder Company, Wilmington, DeL, acorporation of Delaware I Application November 21, 1942, Serial No.466,391

3 Claims.

This invention relates to an improved machine for charging detonatorshells and similar articles with explosives.

Heretofore equipment used for the chargin Having now indicated in ageneral way the nature and purpose of this invention, there follows amore detailed description of the preferred embodiment thereof withreference to the accomof detonator shells With explosives has not beenpanying drawing in which: provided with means adapted to insure auniform Fig. 1 is an elevational View, partly in section, weight ofcharge of explosive. It is common pracshowing the improved explosivecharging device tice in charging detonator shells to dump the ex incharge receiving position. plosive on the top side of a charging platecon- Fig. 2 is a fragmentary view showing the device sisting of aplurality of explosive receiving bins in charge releasing position. oropenings each having a fixed volume. The ex- Referring to the drawings,numeral 4 indicates plosive is then moved across the face of the plate asupporting means as, for example, a platform by means of a Wiper therebyfilling the openings. or a table supporting the explosive charger indi-The excess explosive spills over the edges of the cated generally at 5through leg supports 6. An charging plate into a suitable catch means.The e p os ve releasing means or dump plate I is held charging plate isthen moved into shell loading in fixed position by means of said legs 6in spaced position in order to dump the fixed volume of relationshipwith said support 4. The dump plate explosive into a detonator shell.This method of l is provided with a plurality of openings 8 unichargingby spilling the explosive into the charg formly spaced throughout theplate. The number ing plate openings permits considerable variations ofopenings depends upon the number of shells in the weight of the chargeof explosive delivered desired to be charged at a single operation andtoeach detonator or series of detonators, because may be as many as 500.variations occur in the volume of the charge Spaced from the dump plate1 is an explosive (even though each opening in the charging platestorage means or plate 9 provided with a pluralit is of the same volume)due to the tendency for of explosive receiving bins or openings I0.These the wiper or explosive moving means to carry a bins may be conicalin shape as shown and may portion of the explosive out of the top ofsome have a capacity sufficient to receive enough exholes and, in othercases, for the wiper to ride plosive to charge five or more consecutiveseries over the explosive leaving extra explosive on the of shellswithout the necessity of charging the charge plate opening. Furthermore,the weight bins with more explosive, of the explosive charge varies withthe degree to The bins are charged by means of an explosive which it ispacked, which varies with the amount storage means or hopper l l adaptedto be slidof explosive being moved across a particular ably moved acrossthe face of the storage plate charge plate opening. When varying weight9 and into registry-with the openings it. As each charges of explosiveare charged into a shell and R5 bin It] comes into registr with themoving hopthe shell is subjected to a pressing operation, per theexplosive l2, which may be mercury fulthere is a tendency for the chargeto be overminate, diazodinitrophenol,pentaerythritol tetrapressed in thecase where an excess of explosive nitrate, etc., drops from the hopperinto the bin. is charged, and to be underpressed when an in- Movement ofthe hopper is regulated to permit sufiicient amount of explosive ischarged. When 10 complete filling of each bin. the priming charge of adetonator is overpressed, An explosive charging means or fixed Weightadefective detonator results which detonator may charge receiving plateor metering plate i3 is fail to explode when put into use. Defectivedetomovably positioned between th storage plate 9 nators are dangerousto work with and may result and the dump plate 1 and provided withexplosive in loss of life. charge receiving openings or chambers Hi.There Therefore, it is an object of this invention to are as manychambersl l as there are bins I0 in provide a charging device fordetonator shells the storage plate and openings 8 in the dump and thelike, whereby a fixed weight of explosive plate. In order to reduce to aminimum the poscharge will always be delivered to the detonator, sibiltyof the sensitive explosive l2 being accithereby insuring uniformpressing of the charge dentally detonated through pinching which wouldin the shell. occur should the explosive be caught between two A furtherobject is to provide means for charghard surfaces, a soft rubber facingl5 and I6 is ing a detonator with a fixed weight of explosive placed onthe surface of the storage plate and charge in an economical, efiicientand safe mandump plate, and soft rubber facing 23 and 24 is n91" 5.5placed on the upper surface of storage plate 9 nator shells 2t.

glas es and on the lower surface of storage hopper II respectively. Thecharging plate I3 moves in sliding contact with and between the spacedrubber facings I5 and I 5 between guides I1 and I8 which limit themovement of the charge plate and permit positive alignment of thechambers I4 with the bins I0 and with the openings 8, respectively.Other guides (not shown) prevent movement of the charging platelaterally to its normal movement.

A suitable vibrating means as, for example. the

vibrating means I9 is attached to the table {land through its controlledoperation the explosive I? may be packed in the chambers It to a;uniform density, Uniform density may be accomplished in the chambers Il, thereby resulting. in explosiv'e charge having a uniform density.Since each chamber i4 is of the same volume and each chamber isuniformly packed, then each shell will receive a fixed Weight charge ofexplosive.

Explosive receiving containers as, for example, detonater shells 26 arecarried in a suitable support means as, for example, shell press block2! which is slid. on the top side' of the table l'b'eneath the charger5. Each shell is moved into registry or axial alignment with acorresponding opening 3 in the dump plate I by reason of the fact thatthe shell press block 2 i" is guided into a predetermined position fixedby means of the guides 22 and other stop means (not shown) located onthe far side of the table 4.

The charger is operated by first moving the chambers I l'out of registrywith the bins I6 by moving the charging plate is to the right relativeto Fig. 1. This movement closes the bottom of each bin. The hopper II isthen moved across the face of the storage plate 9 slowly enough to filleach bin with the explosive I2. The charging plate 'is' then moved tothe left relative to Fig, 1 the guide Il stops the movement at aposition where each chamber I l is in registry with a corresponding binIll, The explosive I2 drops from each bin into the chamber in registrytherewith filling each chamber with a uniform amount of explosive. Thecharging plate is then moved to the right relative to Fig. 1 until eachchamber is in registry with a corresponding opening 8 which movement isdetermined by means of the guide 58. The fixed weight charge ofexplosive drops through the opening 8- into corresponding deto- Theshell press block is then removed from the table and another series ofshells are moved into position under the charger and the same procedurerepeated.

Occasionally the density of a batch of explosive to be charged will varyin respect to the density of another batch of explosive. This densityvariation is a function of the grain size of the explosive. Thus, it maybe readily seen that when the grain size of the explosive isunintentionally increased, a lesser number of rains are received in thechambers I0 and consequently the resulting ill density of the chargewill be less under a given condition of packing than when the regularand desired grain size of explosive is charged under the same conditionsof packing. Where the grain size is smaller than the desired grain size,a greater number of grains of explosive will be received in the chambersand consequently the resulting density of the charge will be greaterthan when a regular grain size is being charged, In order to compensatefor these occasional density variations, it has been found that thevibrator I 9 may be used to bring the density of the charge to apredetermined value regardless of the normal variation in" grain sizewhich may occasionally occur.

It is apparent that the objects of this invention have been attained byproviding an improved machine for charging detonator shells; that themachine in accordancewith the present invention permits uniform weightcharging of detonator shells and the like, eliminates the spilling ofexplosive; all of which is accomplished in a more economical, efficient,and safe manner than heretofore realized.

What I claim and desire to protect by Letters Patent is:

l. In a device for charging explosive containers with a fixed weight ofexplosive, the combination ofa storage plate havinga plurality ofexplosive receiving bins therein; a storage hopper slidable over saidstorage plate; a dump plate with a plurality of openings displaced fromaxial alignment with said bins; and a metering plate in close fittingslidable relationship between saidstorage and dump plates and aplurality of chambers in said metering plate alignable in registry withthe receiving bins and dump plate openings.

2; in a device for charging explosive containers with a fixed weight ofexplosive, the combination of a storage plate having a plurality ofexplosive receiving bins therein; a storage hopper slidable over saidstorage plate; a dump plate with a plurality'of openings displaced fromaxial alignment with said bins; a metering plate in close fittingslidable relationship between said storage and dump plates and'aplurality of chambers in said metering plate align'able in registry withthe receiving bins and dump plate openings; and means fo'r'vibrating theaforesaid device.

In a device for charging explosive containers with a fixed weightofexplosive, the combination of a" storage plate having a plurality ofexplosive receiving bins therein; a storage hopper slidable over saidstorage plate; a resilient facing between the storage hopper and storageplate; a dump plate with a plurality of openings displaced from axialalignment with said bins; a resilient facing on the lower side of saidstorage plate; a resilient facing on the upper side of said dump plate;a metering plate in close fitting slidable relationshipbetween resilientfa'cings on said storage and dump plates and a pluralit of chambers insaid metering plate alignable in registry with the receiving bins anddump plate openings; and means for vibrating the aforesaid device.

EDWARD K. LEFREN.

